The general objective of the proposed research is to establish the conformation and organizational array of selected polypeptides and to relate these to spectral properties such as circular dichroism and nuclear magnetic resonance. More specifically, we plan to uniquely determine the molecular conformation of pyrollidine ring containing polypeptides and to establish the energetics of isomerization about the imide bond. We shall also study the dilute solution properties of very geometrically asymmetric macromolecules to study phase equilibrium and the mechanisms of fibrilformationand gelation. Investigations of the mechanism of salt action on the optical and magnetic properties of nonpyrollidine ring polypeptides will be continued to separate the influence of electronic and conformational changes. It already has been established that isomerization about the amide bond does not occur with these chains. Carbon-13 relaxation studies of the side group motions in the beta form of a polypeptide as well as in simple polypeptides undergoing the helix-coil transition will also be undertaken.